Advise me on my serve?

My coach made me watch some of his old favorite, Pete Sampras, and after watching him serve and volley, I want to serve like Pete. Now, I know people say not to imitate pro's. Sure, fine. But I don't suppose I necessarily want to imitate him, but see exactly what he is doing.
For instance, in this video of Pete:http://www.youtube.com/watch?v=LC99glR53wE

To me the toss appears to behind him...at 12 o clock. How does one hit it with as much MPH and often times flat like Pete out of this toss?

Here is a link to a video of me serving:
I get about 105-110 MPH. I'd like to make it more of a weapon. Something I am more confident to come in and volley off of, which I like to do. http://www.youtube.com/watch?v=OB95Vs_hij0

My basic advice would be to loosen up a bit. Despite the knee bend, your serve seems to mostly revolve around your shoulder. Try to get the momentum moving more forward.

Also, all these movements- thrusting upwith the legs, swinging up and through the ball, allowing the wrist to flex, bending at the waist, and so on, all need to come together so their force combines at exactly the point of striking the ball.

Sometimes, with the nice, modern rackets we have, it is difficult to sense when you have achieved this unity of forces. So, here is my other suggestion. Go out (like to a thrift shop) and find an old wooden racket and practice with that for a while (when no one is looking). Unless your form/timing is nearly perfect, serving with it will be a miserable experience. When you can, finally, start serving them in at the same speed as you do now, then switch back to the modern racket. You may find you are getting a bit more pop on the ball.

Sampras had what Yandell called a "left ball position" on his toss, what I think you are calling behind him. A key to understanding this is first that the ball is not behind him, it is actually significantly more out front than your toss - Sampras was quite athletic with an impressive vertical jump and really moved up and forward into the serve. And second, Sampras had a lot of body rotation and a fair amount of spin even on his flat serve. That leftward position allowed him to generate a lot of topspin, but it is a very athletic position that most less explosive people have difficulty duplicating.

In your video, it looks like you're pretty much going straight up and down with your legs. That may be the camera angle, but you definitely don't have the forward spring of Sampras. So when you attempt the "left ball position" at the end of the video, you basically look like you are falling over backwards.

My advice at the moment is to give up on the radical left position and work at more leaping up and to the ball while ending up landing in a balanced position on one foot in the court. The falling over backwards isn't doing your serve any favors.

pretty good. its a lil tough to see from the angle, but you have good motion. looks like you are holding it with extreme grip too for more spin. the onyl thing that stuck out to me is you kinda pause too long when loading up. i would say try making it more fluid so you dont have that pause. but some pros have the pause too.

These images have been posted many times here, but perhaps they will clear up misconceptions about Pete's serve.

In this sequence you can see that his contact point was well into the court:

While you have to look closely for the ball at contact in pic 7, it is about 2 feet inside the baseline.

Note also how Pete really throws his left side into the court in a cartwheel movement, while you don't.
That is at contact in pic 7, his right shoulder is pointed straight up and his left shoulder is pointed straight down.

Here is another view at contact to emphasize how vertical the shoulder orientation is at contact:

And yet less than a second before in his trophy pose, it was his tossing shoulder that was straight up while his hitting shoulder was straight down.

So that rapid reversal of the shoulder angle, or cartwheel, propels the whole left side of the body almost straight up in pics 1-7 above, but also into the court as well.

Because he throws the left side of the body so forcefully into the court, he lands on his left leg, with his right leg kicking straight back in pic 12.

I think the above will be easier for you to work on than the following which usually presents more of a timing problem.

But in addition to the source of power that Sampras gets from that big cartwheel movement, he also has a huge coil/uncoil movement.

From the pics above you can see that while tossing, and shortly after he releases the ball he literally turns his back to face court he is serving into.

That is how he is leading with his back in his trophy position in pic 1 of the first photo sequence at the top of this post.

Finally, on that first sequence note that Pete gets WAY up there from his powerful leg push off. He has some serious hang time in pics 7-10 above.

As others have pointed out there is only one Pete Sampras. It is great to add elements of his serve - bigger leg push off, bigger cartwheel, and bigger coil/uncoil to your serve. Just don't expect as a mere mortal that you will exactly duplicate his motion.

Still, you might also get a kick out of Ian from Essential tennis in a comparison of a pretty impressive duplication of Pete's serve compared to the original. I think you might find some of Ian's commentary would provide additional hints on how to improve your serve.
Sampras Tennis Serve Comparison http://www.youtube.com/watch?v=jDHDS9G9sKw

Sampras had what Yandell called a "left ball position" on his toss, what I think you are calling behind him. A key to understanding this is first that the ball is not behind him, it is actually significantly more out front than your toss - Sampras was quite athletic with an impressive vertical jump and really moved up and forward into the serve. And second, Sampras had a lot of body rotation and a fair amount of spin even on his flat serve. That leftward position allowed him to generate a lot of topspin, but it is a very athletic position that most less explosive people have difficulty duplicating.

In your video, it looks like you're pretty much going straight up and down with your legs. That may be the camera angle, but you definitely don't have the forward spring of Sampras. So when you attempt the "left ball position" at the end of the video, you basically look like you are falling over backwards.

My advice at the moment is to give up on the radical left position and work at more leaping up and to the ball while ending up landing in a balanced position on one foot in the court. The falling over backwards isn't doing your serve any favors.

Click to expand...

Where can I read what Yandell writes about this? Do I have to subscribe to his site?

1) Move the camera closer so that your feet and tip of your racket are always just within the frame (about 5% extra at top, bottom, sides).
Always include the ball impact.

2) Shoot your video in bright direct sunlight. Your smartphone camera has an AUTO exposure control and that probably will select a fast shutter speed in bright sunlight. The faster the shutter speed the less motion blur.

3) The motion of the serve is too fast to show at 30 fps or 60 fps. You need high speed video to see what is really happening. Search - Youtube + Sampras + serve + high speed video There are lots of quality high speed videos of serves.

4) With high speed video you can see the fastest parts of the service motion adequately.

Stop-action single-frame is not that good on Vimeo or Youtube. The best that can be done viewing on site is to click the play-pause button as fast as possible. (If anyone downloads and views with Quicktime please let us know how the video works for stop action using the Quicktime forward & backward arrows.)

Notice: the straight arm at impact, the angle between the straight arm and the racket, the near straight line between his two shoulders and arm. Most importantly, you can see the largest contributor to racket head speed at impact - internal shoulder rotation (ISR) (misnamed in usage 'pronation'). ISR can be seen by the very rapid rotation of the elbow bones, the rotation lasts only about 0.03 seconds. There are many discussions on this forum on internal shoulder rotation. Search this forum - serve + internal shoulder rotation + Toly etc.

Notice: The trunk angle, upright arm and racket, arm angle to body. Interestingly, the players seem to not be looking at the ball at impact perhaps because of the stress on the neck forces them to look down. ?